Yaskawa AC Drive-P1000 Industrial Fan - Manual (Page 263)

5.9 n: Special Adjustments
These parameters control a variety of specialized adjustments and functions, including Hunting Prevention, High Slip Braking,
and Overexcitation Braking.
u n1: Hunting Prevention
Hunting Prevention prevents the drive from hunting as a result of low inertia and operating with light load. Hunting often
occurs with a high carrier frequency and an output frequency below 30 Hz.
n n1-01: Hunting Prevention Selection
Enables or disables the Hunting Prevention function.
Note: This function is available only when using V/f Control. Disable Hunting Prevention when drive response is more important than suppressing
motor oscillation. This function may be disabled without problems in applications with high inertia loads or relatively heavy loads.
No. Name Setting Range Default
n1-01 Hunting Prevention Selection 0, 1 1
Setting 0: Disabled
Setting 1: Enabled
n n1-02: Hunting Prevention Gain Setting
Sets the gain for the Hunting Prevention Function.
No. Name Setting Range Default
n1-02 Hunting Prevention Gain Setting 0.00 to 2.50 1.00
Although this parameter rarely needs to be changed, it may require adjustment in the following situations:
• If the motor vibrates while lightly loaded and n1-01 = 1, increase the gain by 0.1 until vibration ceases.
• If the motor stalls while n1-01 = 1, decrease the gain by 0.1 until the stalling ceases.
n n1-03: Hunting Prevention Time Constant
Determines the responsiveness of the Hunting Prevention function (affects the primary delay time for Hunting Prevention).
No. Name Setting Range Default
n1-03 Hunting Prevention Time Constant 0 to 500 ms
Determined by
o2-04
Although this parameter rarely needs to be changed, it may require adjustment in the following situations:
• Increase this value for applications with a large load inertia. A higher setting leads to slower response, which can result in
oscillation at lower frequencies.
• Lower this setting if oscillation occurs at low speed.
n n1-05: Hunting Prevention Gain while in Reverse
This parameter functions the same as n1-02, except it is used when rotating in reverse. See the explanation for n1-02.
Note: n1-02 is enabled for forward and reverse operation when n1-05 = 0.0 ms.
No. Name Setting Range Default
n1-05 Hunting Prevention Gain while in Reverse 0.00 to 2.50 0.00
u n3: High Slip Braking (HSB) and Overexcitation Braking
n High Slip Braking (V/f)
HSB works in V/f Control only and decreases the stopping time compared to normal deceleration without using dynamic
braking options. HSB reduces the output frequency in large steps to stop the motor and produce a high slip, which dissipates
the regenerative energy created from decelerating the load in the motor windings. Due to the increased temperature of the
motor windings, do not use HSB to frequently stop the motor. The duty cycle should be around 5% or lower.
5.9 n: Special Adjustments
YASKAWA SIEP YAIP1U 01B AC Drive - P1000 Technical Manual 263
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Parameter Details